2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include <linux/percpu.h>
7 #include <asm/pgalloc.h>
12 #include <linux/sched.h>
13 #include <linux/module.h>
14 #include <linux/threads.h>
15 #include <linux/interrupt.h>
16 #include <linux/err.h>
17 #include <linux/hardirq.h>
19 #include <asm/processor.h>
20 #include <asm/spinlock.h>
25 /* Per CPU bogomips and other parameters
26 * The only piece used here is the ipi pipe, which is set before SMP is
27 * started and never changed.
29 struct cpuinfo_um cpu_data[NR_CPUS];
31 /* A statistic, can be a little off */
32 int num_reschedules_sent = 0;
34 /* Not changed after boot */
35 struct task_struct *idle_threads[NR_CPUS];
37 void smp_send_reschedule(int cpu)
39 os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
40 num_reschedules_sent++;
43 void smp_send_stop(void)
47 printk(KERN_INFO "Stopping all CPUs...");
48 for (i = 0; i < num_online_cpus(); i++) {
49 if (i == current_thread->cpu)
51 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
53 printk(KERN_CONT "done\n");
56 static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
57 static cpumask_t cpu_callin_map = CPU_MASK_NONE;
59 static int idle_proc(void *cpup)
61 int cpu = (int) cpup, err;
63 err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
65 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
67 os_set_fd_async(cpu_data[cpu].ipi_pipe[0]);
70 if (cpu_test_and_set(cpu, cpu_callin_map)) {
71 printk(KERN_ERR "huh, CPU#%d already present??\n", cpu);
75 while (!cpu_isset(cpu, smp_commenced_mask))
78 notify_cpu_starting(cpu);
79 set_cpu_online(cpu, true);
84 static struct task_struct *idle_thread(int cpu)
86 struct task_struct *new_task;
88 current->thread.request.u.thread.proc = idle_proc;
89 current->thread.request.u.thread.arg = (void *) cpu;
90 new_task = fork_idle(cpu);
92 panic("copy_process failed in idle_thread, error = %ld",
95 cpu_tasks[cpu] = ((struct cpu_task)
96 { .pid = new_task->thread.mode.tt.extern_pid,
98 idle_threads[cpu] = new_task;
99 panic("skas mode doesn't support SMP");
103 void smp_prepare_cpus(unsigned int maxcpus)
105 struct task_struct *idle;
106 unsigned long waittime;
107 int err, cpu, me = smp_processor_id();
110 for (i = 0; i < ncpus; ++i)
111 set_cpu_possible(i, true);
113 set_cpu_online(me, true);
114 cpu_set(me, cpu_callin_map);
116 err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
118 panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
120 os_set_fd_async(cpu_data[me].ipi_pipe[0]);
122 for (cpu = 1; cpu < ncpus; cpu++) {
123 printk(KERN_INFO "Booting processor %d...\n", cpu);
125 idle = idle_thread(cpu);
127 init_idle(idle, cpu);
129 waittime = 200000000;
130 while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
133 printk(KERN_INFO "%s\n",
134 cpu_isset(cpu, cpu_calling_map) ? "done" : "failed");
138 void smp_prepare_boot_cpu(void)
140 set_cpu_online(smp_processor_id(), true);
143 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
145 cpu_set(cpu, smp_commenced_mask);
146 while (!cpu_online(cpu))
151 int setup_profiling_timer(unsigned int multiplier)
153 printk(KERN_INFO "setup_profiling_timer\n");
157 void smp_call_function_slave(int cpu);
159 void IPI_handler(int cpu)
164 fd = cpu_data[cpu].ipi_pipe[0];
165 while (os_read_file(fd, &c, 1) == 1) {
168 smp_call_function_slave(cpu);
176 printk(KERN_INFO "CPU#%d stopping\n", cpu);
182 printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n",
189 int hard_smp_processor_id(void)
191 return pid_to_processor_id(os_getpid());
194 static DEFINE_SPINLOCK(call_lock);
195 static atomic_t scf_started;
196 static atomic_t scf_finished;
197 static void (*func)(void *info);
200 void smp_call_function_slave(int cpu)
202 atomic_inc(&scf_started);
204 atomic_inc(&scf_finished);
207 int smp_call_function(void (*_func)(void *info), void *_info, int wait)
209 int cpus = num_online_cpus() - 1;
215 /* Can deadlock when called with interrupts disabled */
216 WARN_ON(irqs_disabled());
218 spin_lock_bh(&call_lock);
219 atomic_set(&scf_started, 0);
220 atomic_set(&scf_finished, 0);
224 for_each_online_cpu(i)
225 os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
227 while (atomic_read(&scf_started) != cpus)
231 while (atomic_read(&scf_finished) != cpus)
234 spin_unlock_bh(&call_lock);